99 Ron

[AndyS]

Does it not take the ECU a few days to adjust to the differant fuel 

If it does, that would invalidate the test 

[blackmagic]

^^ what I said then. 

Just to add at my work when a lot of the company cars were petrol. I tried vpower etc in a passat + skoda 1.8t which made a difference in performance. But in a 2.0 20v or 8v passat (none turbo) made no difference at all.

Most cars at work now tdi so can't do much testing since.
I think if you put it in a car designed for it or turbo then you'll get a gain else wouldn't bother.

Just what Ive found over the years. I'm only taking performance mind.

Try a few tanks and see what u think

[scottm72]

I'd agree to an extent that using super unleaded can cause a placebo effect... However when I was on holiday my dad used my car and put half a tank or 95 in it. When I drove the car upon return it was noticeably flat between 4-5.5k revs and only found out later that day that he had put in 95 RON. It might not make a performance difference in the cars they tend to perform this test on (1.4 astras and the like) but it does in the GTI 

watch this -------     

im sure it is better for the engine but would just like to see some evidence of that